CXCL8 and infection: The IL-8 serum levels in 5b WT-infected piglets were significant higher than in 5b ΔAdh-infected piglets at 6, 12, 24, 48, 72, 96, 120, 144 and 168 h post-infection (p < 0.05, Fig. 8C), which is consistent with the in vitro results.